Irrespective of their intended purpose, which can be the practicing of shooting sports or shooting training for the police, military and similar security organizations, shooting ranges are provided with projectile stopping devices. These devices can be used in closed rooms or out in the open and should prevent unintentional or uncontrollable projectile movements outside the shooting range in that contacting projectiles should be braked (decelerated) to a stop without any occurrence of ricochet, and should be stopped in this way within a defined space limited by the projectile stopping device. The projectiles should also be recoverable in a simple and, in particular, complete manner in order to enable them to be disposed of properly.
The disposal of projectiles, which include at least a considerable considerable lead content is of great importance not only for economically motivated recycling reasons. The penetration of lead into the environment, whether via the groundwater in chemically dissolved form or via the air as lead dust holds considerable potential danger not least because of the dispersion paths which are difficult to monitor and the immediate results which cannot be estimated at present, but also subsequent damage and the many ways in which it could manifest itself and the long-term effects still to be anticipated.
Along with the growing environmental sensitivity, which has also been reflected in an increasing number of official publications for the operators of shooting installations, but also motivated by reasons of cost, there is therefore a requirement for a projectile stopping device able to meet the above-mentioned requirements.
Projectile stopping devices are basically known in the form of simple earth or sand mounds which, however, both from the point of view of the avoidance of heavy metal penetration into the earth and also the costly cleansing of earth loaded with heavy metals, are to be regarded as extremely questionable.
German Pat. No. DE-PS 858 951 discloses a projectile stopping device which consists of a stopping box formed from wood which, on the firing side, is covered by a target disc. Behind the target disc are a plurality of projectile stopping curtains located spaced apart from each other in the firing direction. These curtains consist in part of foam rubber and in part of another soft material, such as rubber, and are disposed in a freely hanging manner. A part of these plate-like stopping curtains is provided with vertical slits. A fundamentally similar projectile stopping device is known from German Pat. No. DE 28 39 509 A1, wherein the individual stopping curtains which lie one behind the other in the firing direction are formed by plates of hard rubber, which is reinforced with synthetic fiber mats or with woven wire. Alternatively, the use of an earth wall as the projectile stopping device is also known from this document. The stopping curtains consisting of rubber materials are encumbered by the problem that, in dependence upon the absolute thickness, projectiles remain stuck therein and must be separated by a special working process for disposal purposes. In addition, in dependence upon the frequency of firing, the further problem occurs of more or less severe wearing and therefore the necessity for the complete exchange of individual stopping curtains.
From German Pat. No. DE 88 13 708.2 a projectile stopping device is known, of which the individual stopping curtains are formed by a side by side arrangement of pipes, the walls of which are intended to be shot through and inside which are located further stopping bodies in the form of strip-like inserts in order to improve the stopping effect. Both the pipes and the strip-like inserts can, according to this document, consist of a rubber material reinforced by a woven fabric, such as parts from worn out conveyer belts. The pipes can, however, also consist of aluminum. An essential feature of this known projectile stopping device is therefore specially produced stopping bodies, wherein as a result of their formation intended to be shot through, the problem of disposing of the projectiles, in particular the separation of projectiles and projectile stopping material is again present.
Finally, a further projectile stopping device is known from German Pat. No. DE 44 10 342 A1, which in the main region consists, by virtue of an arrangement of plates at a spaced disposition one behind the other, of mutually spaced plates of rubber material reinforced by woven fabric, e.g. used parts of a conveyor belt, whereas the other regions, which are not subjected to comparably intensive firing, are characterized by a layered arrangement of projectile stopping blocks consisting, for example, of thermoplastic materials.
With respect to the disposal of the projectiles, in particular the separation of projectiles and projectile stopping material and with respect to wear, the statements already presented above in connection with the other projectile stopping devices of the prior art are true.
It is therefore the object of the invention to form a projectile stopping device of the type mentioned in the introduction in such a way that in addition to an operation which is safe and which harms the environment as little as possible, it is possible to catch the projectiles in a reliable manner and to dispose of the projectiles in a proper cost effective manner. This object is achieved in such a projectile stopping device according to the present invention which provides a projectile stopping device having a first stopping curtain and a second stopping curtain disposed behind the first stopping curtain relative to a firing direction. Each of the stopping curtains comprises a side by side arrangement of steel cables.
The projectile stopping device consists, amongst other things, of a plurality of stopping curtains disposed one behind the other in the firing direction. The curtains are intended to exert a braking effect (decelerate) on the projectiles coming into contact with them. The number of these stopping curtains is selected in dependence upon the maximum caliber or the maximum value of the projectile energy of the projectiles used and the braking capacity of the individual stopping curtain. In accordance with the invention, the individual stopping curtains consist of a side by side arrangement of steel cables, which by reason of their mechanical properties are particularly suited to being projectile stopping bodies. The act of firing at a steel cable which preferably hangs in such a way as to be able to swing, by reason of its composition of individual wire elements which are in frictional contact and therefore have a strong damping effect, is linked to an only moderate propagation of noise. According to its respective strength properties and the projectile energy to be received, the individual steel cable has a long service life within the projectile stopping device before an exchange is required. Contacting projectiles are braked in succession by the stopping curtains and simply fall to the floor between these curtains so that in conjunction with receiving containers on the floor an extremely simple recovery and disposal of the projectiles is possible. An expensive working process relating to separation of the projectiles from the stopping device is therefore avoided. Steel cables as the starting material for a stopping device in accordance with the invention are also found as waste materials in many machines and installations and are therefore available as an inexpensive raw material which must merely be cut to a length corresponding to the dimensions of the firing field. Steel cables are frequently found in a condition heavily soiled with lubricants which makes them undesirable for otherwise simple disposal as scrap metal. Accordingly, use of steel cables in accordance with the invention also allows for improved use of waste materials.
The steel cables of a stopping curtain can be disposed spaced apart from each other. In this case, a large number of stopping curtains are required in order to provide a gap-free covering of the firing field. In contrast, it is particularly advantageous if the steel cables of a stopping curtain are peripherally tangential to each other. This achieves a considerable increase in the braking property of the individual stopping curtain since a lateral displacement of an individual steel cable is always associated with a simultaneous displacement of other steel cables of the respective stopping curtain and consequently with a higher conversion of energy.
According to an embodiment of the present invention, the steel cables of the individual stopping curtains are disposed offset from each other in order to achieve a gap-free covering of the firing field, and in particular, both in the case of stopping curtains of which the steel cables are tangential to each other and also in those which are disposed laterally spaced from each other.
As a rule, the dimensions of the steel cables of a stopping curtain are of the same size. In dependence upon a desired braking property whichxe2x80x94seen in the firing directionxe2x80x94can also be different, the parameters, characterizing the braking properties, of the steel cables of the stopping curtains can also differ accordingly. In addition to the cross-section or the weight, characterizing parameters may also include the characteristic strength values.
According to the features of another embodiment, the stopping curtains are hung on a transverse carrier mounted in such a way as to swing freely about a horizontal axis. This type of attachment of the stopping curtains improves the movement possibilities of the steel cables and their braking properties since the swinging movements of the transverse carrier and of the steel cable can be compounded and result in an extended deflection movement of the steel cable. A transverse carrier provided with stopping curtains can be providedxe2x80x94it is also possible for a plurality of transverse carriers to be provided which extend parallel to each other, can swing about their respective longitudinal axis and are each fitted with at least one stopping curtain.
According to the features of another embodiment, the steel cables are preferably releasably connected with the transverse carrier.
According to the features of another embodiment, the steel cables are suspended in such a way that they are free to swing to all sides. This is of particular significance for the steel cables located at the lateral edge regions.
In accordance with the features of another embodiment of the invention, the stopping cables take up a defined initial position within each stopping curtain, which position can be reproduced in the case of a deflection of the stopping cable as a result of firing since a return force returns the stopping cable to the initial position. This return force can be produced in the most simple case by spacers, thereby by means of an additional weight disposed on an end of the stopping cable. These spacers, however, have a further positive effect in that twisting of individual stopping cables is effectively prevented thereby. This in turn facilitates the exchange of individual damaged stopping cables. In the most simple case a spacer can be formed, for example, by a flat iron which is attached to stopping cables laterally, i.e. at the sides of two stopping cables facing each other within a stopping curtain.
According to the features of another embodiment of the invention, the stopping cables of the individual stopping curtains are guided at the top and bottom. The mechanical connections between the guides and the stopping cables are formed in such a way that the stopping cables can be deflected to a limited extent by projectiles striking them but during this deflection are subject to a return force towards their initial position. This return force can be gravityxe2x80x94but the possibility of suspending the stopping cables with intermediate positioning of tension springs should also be considered. As a rule, the stopping cables are disposed vertically, however, a horizontal arrangement is equally possible in this case. In each case a plurality of such stopping curtains are disposed one behind the otherxe2x80x94seen in the firing direction, wherein the stopping cables of successive stopping curtains are disposed offset with respect to each other so that projectiles which strike between two stopping cables of a first curtain always undergo reliable braking by the stopping cables of the following stopping curtain. As a result of the stopping cables being guided at both sides and defined at both ends, by means of which the function of spacers is also provided, a simple exchange of individual stopping cables is possible since adjoining stopping cables can be prevented from twisting together as a result of being fired upon.
Maintenance work and down-times of the projectile stopping installation caused by such work can in this way be reduced with respect to the prior art.
According to the features of another embodiment, each stopping cable is provided at both ends with a receiving device to which it is firmly connected. In such an embodiment, the receiving device is adapted to the guide and is formed in such a way that a simple release of the connection between the receiving device on the one hand and the guide on the other hand is possible. The use of standardized receiving devices for the stopping cables, which are preferably formed in the same way at both ends, make it possible for each stopping cable to provide reproducible and in particular uniform deflection conditions with respect to a rest position. If required, a resilient element can be simultaneously integrated into the receiving device, by means of which element the stopping cable is connected to this receiving device.
The features of some embodiments of the present invention are directed at different types of physical arrangement of the stopping curtains with respect to the firing direction. In the most simple case, these stopping curtains are formed flat and the respective planes thereof extend normal to the firing direction. The plane of the individual stopping curtains can, however, also equally be disposed to pivot about a vertical axis with respect to the normal direction, wherein a pivot movement about a horizontal axis or about a horizontal and a vertical axis can also be provided. The different types of inclined arrangements of the stopping curtains offer the particular advantage that ricochets can be deflected over the shortest distance. It can also be of particular advantage in this connection that the projectile stopping device is formed by a plurality of groups of respectively planar stopping curtains, wherein the individual groups in turn extend at an angle to each other. This offers a particularly reliable stopping possibility even for ricochets or projectiles otherwise contacting the curtain at unusual angles.
According to the features of another embodiment, the stopping curtains can equally also extend along physically curved surfaces. This merely depends on the physical arrangement and formation of the guides allocated to the stopping cables. Also in this way, a stopping curtain can be produced, for example, which is formed in a U-shape, as seen in a horizontal cross-section.
The features of additonal embodiments of the invention are directed to an exemplified formation of a receiving device. This consists of a receiving part intended to receive a cable end and of a holding profile which is in preferably releasable connection with the receiving part. This connection can, for example, be a welded connection, wherein in the welding process the cable end facing the receiving part can be bound in at the same time.
According to additional features of the invention, each guide is formed by an arrangement of carrier pipes or rails which are disposed outside a target field. They can be disposed, for example, to be protected from contacting projectiles by cover plates. Both the carrier pipes and also the rails are naturally adapted to the actual formation of the holding profile, in particular to the permissible deflection movements of the stopping cables.
The features of still further embodiments of the invention are directed at the guide formed by the carrier pipes. The holding profile can, according to these embodiments, be formed in such a way, for example, that it passes through the intermediate space between two horizontally extending carrier pipes and a profile element of the holding profile engages over the top of the two carrier pipes. Alternatively, the profile part can also be formed in such a way that engagement takes place over only one carrier pipe. Such a formation of the element pairing: holding profile/carrier pipe is particularly advantageous where assembly and disassembly of a carrier cable is possible by a simple hanging movement of the holding profile perpendicular to the axis of the carrier pipe, in particular when the carrier pipes extend in the plane of the stopping curtain or of the curved surface, in which the stopping curtain extends. This facilitates, for example, removal and replacement of a stopping cable located in the middle of a stopping curtain. The guides can, however, equally also be formed by a plurality of comparatively short carrier pipes or comparable components which extend individually perpendicular to the plane or the surfaces of the stopping curtains so that from the end faces of the carrier pipes, the individual stopping cable or its holding device can be pushed on.
In another embodiment, all components of the projectile stopping device are held in a frame structure. The device as a whole can be designed to be set up in closed rooms, however, it is possible to consider setting it up in the open. In particular, it may also be a mobile installation.
The projectile stopping device can include a screen having plates and which frames the firing field. The plates should extend at an acute angle with respect to the firing direction and frame the firing field at least laterally and at the top. There may also be rearward and lateral enclosure of the arrangement of the stopping curtains with projectile proof plates, such as steel plates. These features are directed at limiting the firing field and the space receiving the stopping curtains. The screen forms a mechanical protection for the region to the side of the stopping curtains, amongst others also for the transverse carrier(s). By reason of its angled orientation it is ensured that no projectiles can ricochet back into the space in front of the projectile stopping device. The screen consists of projectile-proof plates which like side walls, which shut off the space behind the projectile stopping device and to the side thereof, can also consist of steel.